1. Field of the Invention
The present invention is generally related to pneumatic transport systems and more particularly, to a single line pressure/vacuum system.
2. General Background
Pneumatic transport systems are typically used by banks and other commercial institutions for delivering and receiving materials encased in a container specifically designed to be compatible with the system. Systems which the inventor is familiar with include the following.
U.S. Pat. No. 4,436,456 to Thomas entitled "Pneumatic Communication System For Banking And The Like" discloses a pair of upright customer and teller terminals joined at right angles at their lower ends by a carrier transit tube. Each terminal includes a carrier elevator, a blower, and special ducting for using both blowers to raise the elevator and carrier at the receiving terminal. Air valves at each terminal influence the movement of the carrier.
U.S. Pat. No. 3,948,466 to Rudder, et al. entitled "Pneumatic Carrier Send And Receive Terminal" discloses a movable horizontal tray alignable with a horizontal pneumatic tube connected to a terminal. A carrier sealing ring on the end of the tray is aligned with the tube and surrounds the gasket of a received carrier. Cams are used to push the carrier out of the ring when the tray is moved out of the terminal and to engage and push the carrier in the ring when the carrier is replaced and the tray is retracted.
U.S. Pat. No. 4,941,777 to Kieronski entitled "Apparatus For Conveying Material" discloses a reversible blower system that conveys a carrier member through a tube by suction from one terminal to an intermediate location and by pneumatic pressure from the intermediate location to the other terminal, and vice-versa. The carrier member is gradually retarded and stopped at each terminal by a yieldable plate. A double tube arrangement is used to provide the combined suction and pressure.
U.S. Pat. No. 3,612,438 to Herndon entitled "Pneumatic Transport Apparatus" discloses a transport device wherein the carrier utilizes fins to stabilize it during its travel within a winding hollow rigid tube system.
U.S. Pat. No. 4,251,169 to Kelly, et al. entitled "Single Line Pneumatic Tube System" discloses a single-blind pneumatic tube system capable of incorporating one or more intermediate stations.
U.S. Pat. No. 4,820,086 also to Kieronski entitled "Pneumatic Tube Carrier System And Method" discloses a system that includes means for automatically removing the contents from the carrier at a terminal before returning the carrier to the other terminal.
U.S. Pat. No. 4,256,418 to Stangl entitled "Pneumatic Tube Station" discloses a displaceable tube portion that can be moved parallel to itself out of a continuous delivery tube. When inserted in the delivery tube, the displaceable portion is connected at both ends with the delivery tube.
U.S. Pat. No. 4,437,797 to Kardinal entitled "Pneumatic Mail Station For The Delivery, Pneumatically Decelerated Reception And Transit Of The Pneumatic Dispatch Cases" discloses a reception tube chamber closed at one end and a transit tube chamber open at both ends. First and second reception tube chambers that are connected provide pneumatic deceleration proportional to the kinetic energy of an incoming pneumatic dispatch case.
Although a variety of systems are known, all require motors at each end of the system, a plurality of tubes for providing suction and pressure, long radius bins to traverse corners or some special form of operator interaction at each end of the system for receiving and sealing the items to be transported in the carrier and then ensuring that the carrier is properly positioned for transportation through the system. This leaves a need for a system that can be operated from one end and that has all motors and controls at one end.